1. Field of the Invention
The invention herein aims to provide a sewing machine, with a structure of a horizontally oriented and vertically extended transverse tube-shaped fabric feed needle plate base disposed below the needle holder of the sewing machine and a drive mechanism with the drive revolving shuttle and the fabric feed tooth plate situated in the interior section; with the modifications afforded by the said drive mechanism, the size of the interior section of the fabric feed needle plate base can be reduced to a narrow tube beam-shape for making variation in the type of stitch along with the style of the pattern cam of the sewing machine main body, capable of not only increasing the sturdier sewing and attractive appearance of the objects being processed, but also enabling the sewing machines industry to create and enhance the product quality and the added value of the productivity.
2. Description of the Prior Art
Referring to FIG. 8, an isometric drawing of the external view of a conventional level platform-type sewing machine structure, wherein, the sewing machine (B) has disposed at its bottom section (below the needle holder (B6)) a level platform-type fabric feed needle plate base (B7) structure and, as indicated in FIGS. 1 and 2, a dog base plate (B71) is situated at the interior section of the fabric feed needle plate base (B7) which facilitates the installation of a fabric feed dog (B72) at the top section of the dog base plate (B71), and since one end of the dog base plate (B71) is conjoined to an eccentric shaft (B11) at the end tail of another main shaft (B1xe2x80x2) on the bottom panel via a connecting rod (B73), and the other end is conjoined to a rocker arm (B74), therefore, when the main shaft (B1xe2x80x2) on the bottom panel is driven by the belt (C) and rotates along with the main shaft (B1), this initiates the repeated movement of the dog base plate (B71) following path shown in FIG. 3 and furthermore, there is a press foot (B75) at the upper extend of the fabric feed needle plate base (B7), when the dog base plate (B71) ascends, the fabric feed dog (B72) and the press foot (B75) grasp the object being processed (D) between them such that the object being processed (D) becomes taut, at which time, the fabric feed dog (B72) moves forward and backward (in the direction of the operator) along with the dog base plate (B71), and after the object being processed (D) is pulled a given distance, the dog base plate (B71) descends and releases the object being processed (D), and then the dog base plate (B71) moves forward and backward to the other side such that when the dog base plate (B71) ascends once again and contacts the object being processed (D), the repetitive said routine completes the sewing action of the needle holder (B6); furthermore, a pattern cam (A) structure is situated inside the head section of the sewing machine (B), and the pattern cam (A) is mainly coupled to a transverse main shaft (B1) and rotates along with the main shaft (B1); an idler wheel fixture (B3) rests against the pattern cam (A) and is linked to a needle holder fixture (B5) via a connecting rod (B4) such that when the main shaft (B1) of the sewing machine (B) rotates and drives the needle holder (B6) upward and downward, the pattern cam (A) is thus driven by the transverse shaft (B2) to rotate and cause the idler wheel fixture (B3) to swing following the sinusoidal surface of the pattern cam (A) and to drive the connecting rod (B4) to repeatedly push the needle holder fixture (B5) leftward and rightward, while the needle holder (B6) of the sewing machine (B) moves upward and downward to sew the object being processed (D) to collectively generate a left and right transverse movement and thereby effectively accomplish a variable herringbone stitch as the object being processed (D) is conveyed straight ahead.
In addition, a revolving shuttle (B8) structure is disposed within the interior section of the fabric feed needle plate base (B7), the revolving shuttle (B8)is mainly connected by a drive mechanism (B81) to rotation along with the main shaft (B1xe2x80x2) such that as the needle holder (B6) descends, the threads in the inner section of the revolving shuttle (B18) and in the sewing needle (B61) at the bottom end of the needle holder (B6) can conduct a stitching routine that achieves the purpose of sewing the object being processed (D); furthermore, since for adapting to the pattern cam (A) varying the sewn stitching situated inside the fabric feed needle plate base (B7) of the said conventional sewing machine, the drive mechanism disposed within the interior section occupies a space of considerably larger dimensions and, furthermore, in order to drive along with the other main shaft (B1xe2x80x2) on the bottom panel, only a level platform-type design arrangement can be accommodated; however, with regard to the physical characteristic of the object being processed, the level platform-type fabric feed needle plate base does not have positions for a completely flat posturing and cannot be utilized for sewing and finishing irregularly contoured items such as the shapes of tube, arc and pocket of the sleeves or the pants; that interrupts the continuous operation of sewing the object being processed and not only is incapable of effectively maintaining product quality, but leads to decreased productivity as well as product quality.
Therefore, the invention herein, with a horizontally oriented and vertically extended transverse tube-shaped fabric feed needle plate base disposed below the needle holder of the sewing machine and, furthermore, a drive mechanism with the drive revolving shuttle and the fabric feed tooth plate situated in the interior section of the transverse tube-shaped fabric feed needle plate base for making variation in the type of stitch along with the style of the pattern cam of the sewing machine main body and not only for embellishing the objects being processed in the forms of tube, ring, arc and pocket, but also for effectively increasing the sturdier sewing, attractive appearance and the embellishment of the objects being processed through the variations of the herringbone stitches to enhance the product quality and added value of the productivity of sewing machines in this category, takes this as its primary objective.
Another objective of the invention herein is the inclusion of a cam situated at the tail end on the lower sub shaft and, furthermore, a horizontally oriented slot is formed on the bottom section of the dog base plate for an insertion fastening with the cam; the dog base plate also vertically inserted to a sliding block base of a connecting rod set, one of the ends of the sliding block base is conjoined to a swing arm via a connecting rod such that as the lower sub shaft rotates, the dog base plate moves upward and downward through the rotation of the cam, at which time, the sliding block base swings forward and backward through the link of the swing arm, the dog base plate slides upward and downward as well as swings forward and backward following the movement of the cam and the sliding block base; furthermore, the fabric feed dog is situated at the top section of the dog base plate such that as the dog base plate moves, it enables the fabric feed dog on the top section to accomplish the fabric feeding movement, and the fabric feed structure of the original level platform-type fabric feed plate base can be extended into the interior section of the transverse tube-shaped-shaped fabric feed needle plate base embodiment of the present invention.
Yet another objective of the invention herein is the inclusion of a drive shaft directly linked to the drive mechanism of the tube base, and by disposing a gear set at the tail end on the drive shaft and through the meshing among all the gears and the revolving shuttle, the revolving shuttle can be driven directly to rotate, and the revolving shuttle structure of the original level platform-type fabric feed plate base can be extended into the interior section of the transverse tube-shaped fabric feed needle plate base embodiment of the present invention.
To enable a further understanding of the features and the objectives of the invention herein, the brief description of the drawings below is followed by the detailed description of the preferred embodiment.